During operation, machinery may generate sound-causing vibrations. For example, modern aircraft may include various turbine systems such as jet engines (e.g., one or more gas-powered turbine engines), auxiliary power units (APUs), and/or environmental control systems (ECSs). Although such aircraft systems are generally safe, reliable, and efficient, these systems may be sources of noise or other types of unwanted sound, especially during aircraft take-off and landing operations, as well as while an aircraft is idling or taxiing at the airport.
To mitigate sound emanating from aircraft, various types of reduction mechanisms have been developed. Although present approaches exhibit fairly good sound suppression characteristics, there is continuing need for improved attenuation configurations to reduce manufacturing costs and increase effectiveness. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background.